1. Field of the Invention
This invention relates to an image forming method in which at least a dye is moved to and deposited on an electromotive force-generated portion by electromotive force produced by irradiating with light. This invention also relates to an image forming material used in this method.
2. Description of the Related Art
Methods for transferring an image to an unspecialized recording medium such as paper or the like from an electric signal or optical signal, which are currently utilized in a printer or the like, are exemplified by a dot-impact method, thermal transfer method, thermal sublimation method, ink jet method, and laser printing method in electrophotographic methods. These methods are roughly divided into three groups.
In methods of a first group including dot-impact, thermal transfer, and thermal sublimation methods, a sheet such as an ink ribbon, donor film, or the like, which is provided with dispersed dye molecules, is superposed on paper or the like and the dye molecule is transferred to the paper or the like by a mechanical impact or heat. These methods always require expendable supplies and are low in energy efficiency, resulting in high running costs. Also, in these methods except for the thermal sublimation method, the quality of image is poor.
In the ink jet method of the second group, ink is directly transferred to paper from a head and hence no expendable supply except for ink is required, resulting in low running costs. In this ink jet method, however, the minimal image unit is determined by the size and interval of the heads and hence the printing speed decreases with an increase in printing quality. Also, this ink jet method is not very energy efficient.
In the third group, electrophotographic methods using laser printers or the like are exemplified. In these methods, an image is formed via an intermediate transferring member. Specifically, a toner is adsorbed onto an electrostatic latent image formed on a light-sensitive member through a laser spot. This is transferred to paper to form an image. Because of this, it is possible to form a comparatively fine image. Also, only a toner is consumed, resulting in low running costs. There are, however, problems in that this method requires high voltage for the formation of an electrostatic latent image and for the adhesion and transfer of a toner, resulting in high power consumption and the generation of ozone and nitrogen oxides.
Furthermore, there is the problem that operational sounds are large in all of the above printing methods.
On the other hand, an ordinary printing method, silver salt photographic method, and the like are known as image forming methods in which no printer is used. In these methods, an image of high quality can be formed. The ordinary printing method using a printing plate formed for printing is low in running costs when forming a large number of identical images. However, it is unsuitable for general uses. Also, the silver salt photographic method requires the use of a medium such as a photographic film, photographic printing paper, or the like, which is not reusable, resulting in high running costs. Also, in this method, a specific developing process is required and hence real-time printing can not be expected.
As above-mentioned, among the image forming methods currently used, there is no method which forms an image of high quality, is low in running costs, has features of energy and resource savings, does not generate noise and harmful substances, and specifically there is no method which is harmless to both the environment and to users.